Furnace for heat treatment of small articles



s E Y A H FURNACE FOR HEAT TREATMENT OF SMALL ARTICLES Filed July 29,1952 3 Sheets-Sheet 1 all QflINVENTOR BY 2 m ATTORifi May 22, 1934. QHAYES 3,960,219

FURNACE FOR HEAT TREATMENT OF SMALL ARTICLES Filed July 29, 1932 3Sheets-Sheet 2 IN VEN TOR (44$ a; v Mia/734% 4 ATTORNEY M61122, 1934- c.I. HAYES 1,960,219

FURNACE FOR HEAT TREATMENT OF SMALL ARTICLES I Filed July 29, 1932 5Sheets-Sheet 3 INVENTOR BY aw 4m T7 ORNEY Patented May 22, 1934 ITEDrAirss 3P A'TENT lorr es "FURNAoEiFoRnE T TREATMENT OF SMALL ARTICLESCarl I. Hayes, Prot idenceylt. I., assignor to "Harold Cz'Field,Providence, It. I.

Aliplic'ationJuly 29, 1932, Serial No. 625,682

12 Claims.

,My present invention relates to fumace sffor heat treating materials,and has particular reference to improved apparatus for facilitatingheattreatment of small articles.

-The-heat treatment of small articles, such as 'metal needles,forexample, --has heretofore been diiiicult because thearticles tend toclingtogether when quenched in liquid, such as oil or ing fluidcontainer, withresultant lack of uni- :formityof heat treatment,and-inconvenience both in separating the work fromthe; carrier trays andin drying the-trays for additional use.

It has also been found that-quenching the trays has afurther'detrimental eifect in that 7;;26the trays, which are usuallymade of stainless -must be replaced.

-My present invention contemplates the pro- 3 vision of an automaticarrangement for projecting .the heat-subjected articles from the carironor-steel, becomehardened and warped-and the fluid, and the'conveying' ofthe carrier-trays cleaning or drying the'trays is eliminated, and. thetrays are not subjected to quenching and to a separatestorage-receptacle from which they maybe removed asdesired-readyfor use,whereby uniformity of treatment in ensured, need for -do-not hardenorbecome warped.

l rangement of parts" more fully disclosed in the With these and otheradvantageous features T in view, 'theinvention consists of a novelardetailed description following, in conjunction with the accompanyingdrawings, and more fully defined inthe claims appendedhereto.

In the drawings,

'Fig; 1 is a centrallongitudinalvertical section I through a heattreating furnace constructed in broken away; "showing a 'modifiedarrangement;

accordance "with my invention, "on" the line 11 Fig. 3 is a-perspectiveview of the tray holding drum; 7

Fig. 4 is a perspective view'of acarriertray;

Fig. 5 'isa section similar toFig. 1', partly 'Fig. 6isaperspective'view of theconveyor "chainfsupport hearth, and carriertray of the modified arrangement; and

and a sprocket gear 26 mounted thereon, the. rier trays into thequenching fluid in scattered I relation while holding the carrier traysout of Fig; '7 is a perspective fragmentary view 'ing afurthermodification. I

Referringto the drawings, the furnace 10 has showthe usual heat treatingchamber 11 with entrance opening 12 normally closed by a removable door13. An endless conveyor belt or the like 14 is mounted on longitudinallyspaced conveyor drums 15 for movement within the heat treatingchambenfand receives carrier trays lfi-containing articles to be heattreated; an exit chute 1'7 is positioned adjacent the innerend ofthe'conveyor, and communicates through an outlet conduit 18 with aquenching fluid container'l9 for receiving the heat subjected work.

A carrier holding drum 20 is also mounted ad- U jacent the end oftheconveyor, slightly higher thanthe adjacent drum 15; as shown in Fig.3,

the drum comprises two end disks 21 mounted on a shaft 22, and a seriesof rods 23 extending, between'andsecured to the'end disks at theirperiph'eries in parallel alignment to the shaft 22.

The eo r'iveyor drums are suitably supported" on shafts" 24;"one shaft24 having a'power gear'25 shaft22' also having a sprocket "gear 27connected to the sprocket gear 26' by achain 28 for move- "jmntofthe'drum 20 in fixed, timed relation to the movement of the conveyorchain.

' The carrier tray 16, see Fig. 4, has 'sides29 and, a rear end 30having a forwardly extending 'portion 31 positioned above the sides 29to form a hook'32. As the traylfiis moved alongthe con- "veyor'jseeFig.1, it is tilted to permit scattered fallof "the heatv subjected materialinto the quenching fluid andthe hook 32 catches over one"ofthecrossjrods 23 to hold the tray, the tray is lifted "over by therotating tray holding drum 'until it' is" released to'fall'into the exitchute 33 from which it 'f'allsinto the tray receiver 34,, equipped witha hinged cover 35 for facilitating "removal of thestored trays.

'As indicated by the shading, the furnace is suitably heat insulated andpreferably is equipped with a'combustion chamber 38 "adapted to receive,

"predetermined volumes of gas and air for combustion, and an outlet slot3'7 for forming an air excluding curtain of the products of combustion,j 'asdescribed'in my Patent No. 1,724,583. The furnace maybe heated inany suitable manner, but electric heating of the type shown in my abovementioned patent is preferred because of the unifdrmity of heating andthe ease of regulation and control of the treating'temperature.

"Instead of a conveyor belt, such as shown in,

'Fig. 1,'conveyor chains 38 may be used, as shown" no in Figs. 5 and 6.These chains preferably consist of double links 39 and intermediateupstanding connecting blocks 40, whereby the spaces between the blocksmay receive the projecting ends 41 of carrier trays 42; the trays 42have sides 43 and one forward end 44, and are supported by a centralhearth plate or the like 45 as they are dragged along by the carrierchains. The conveyor drums 46 have end disks 47 mounted on a cross shaft48, the end disks being provided with suitable spaced teeth 49 adaptedto enter the double links 39 between the blocks 40.

This construction provides a more positive drive for the carrier trays,and eliminates the need for a separate tray holding drum, as the traysswing downward after leaving the support plate to release the work andthen leave the chain to slide down the exit chute 33 into the trayreceiver.

A further modified construction is indicated in Fig, 7; in thisarrangement trays 42 such as shown in Fig. 6 are utilized with anendless conveyor such as shown in Fig. 1, a tray holder drum 50 havingend disks 51 provided with non-radial slots 52 being utilized to engagethe projecting ends 41 of the carrier trays and thus hold and move thetrays in a manner similar to that shown in Fig. 1.

It is preferred to arrange the quenching tank and the tray receiver soas to exclude atmospheric air from the heating chamber, the exit chutefor the work extending below the surface of the quenching fluid, and thereceiver having but a single exit opening normally tightly closed by thehinged cover plate. For certain classes of work, however, it is notnecessary to exclude atmospheric air, and the tray receiver may beomitted if desired, and replaced by a basket or the like for receivingthe empty trays.

The above described constructions are particularly advantageous for theheat treatment of articles such as metal needles, blades, pins, andother small articles that tend to cling together when thrown into aquenching fluid such as oil;

the sudden swing of the carrier tray and the long drop into the fluidseparates the articles so as to facilitate uniform treatment, and theretention of the tray and its subsequent release to the tray receiver,prevents quenching and wetting of the trays and eliminates cleaning anddrying prior to further use.

While I have described specific constructions, embodying the principlesof my invention, it is clear that such changes in construction, in sizeand in arrangement of the parts as may be de-' sirable to comply withthe requirements for heat treating particular materials may be made,within the spirit and the scope of the invention as defined in theappended claims.

I claim:--

1. In a furnace for heat treatment, a heat treating chamber, saidchamber having an exit chute for heat treated work in the lower portionthereof, means for conveying a work carrying tray through said chamberand over said chute, and for supporting said tray in work carryingposition until it passes over said chute, and means engaging said trayfor swinging support over said chute, whereby the tray swings under theinfluence of gravity to release the work into said chute.

2. In a furnace for heat treatment, a heat treating chamber, means forsupporting a work carrying tray in said chamber, a quenching fluidcontainer communicating with said chamber, a tray receiver communicatingwith said chamber, and means for moving the tray to first release thework into said container and then guide the tray into said receiver.

3. In a furnace for heat treatment, a heat treating chamber, an entranceopening at one end of said chamber, a quenching fluid container and atray receiver at the other end of said chamber, means for conveying workcarrying trays from said entrance opening towards the other end of saidchamber, and means for moving the tray to first release the work intosaid container and then guide the trays into said receiver.

4. In a furnace for heat treatment, a heat treating chamber, means forsupporting a workcarrying tray in said chamber, an exit chute for thework, an exit chute for the tray, and means for guiding the work intothe first exit chute and then guiding the tray into the second exitchute.

5. In a furnace for heat treatment, a heat treating chamber, means forsupporting a work carrying tray in said chamber, an exit chute for thework; an exit chute for the tray, and means for retaining the tray inthe chamber for a predetermined period of'time, then moving the tray torelease the work into the first exit chute and then guiding the trayinto the second exit chute.

6. In a furnace for heat treatment, a heat treating chamber, an entranceopening at one,

end of said chamber, an exit chute for work and an exit chute for workcarrying trays at the other end'of said chamber, means for conveying awork carrying tray from said entrance opening to said exit chutes, andmeans for tilting the tray to release the work into the exit chute forwork,

and for releasing the emptied tray into thev exit chute for trays.

7.-In a furnace for heat treatment, a heat treating chamber, an entranceopening at one end of said chamber, an exit chute for work and an exitchute for work carrying trays at the other end of said chamber, meansfor conveying a work carrying tray from said entrance opening to saidexit chutes, means for tilting the tray to release,

the work into the exit chute for work, means for releasing the emptytray into the exit chute for trays, and means for excluding atmosphericair from said heat treating chamber.

8. In a furnace for heat treatment, a heat,

treating chamber, an exit chute for work and tray adjacent said workexit chute to release the work into said work exit chute, and forshifting said tray and releasing the same into said tray exit chute.

9. In a furnace for heat treatment, a heat treating chamber having aninlet opening at one end,

and spaced exit chutes for work and for work carrying trays at the otherend, a conveyor for conveying work carrying trays through the heattreating chamber, and means for detachably holding said trays forswinging movement adjacent said work exit chute to release the work,shifting the emptied trays adjacent said tray exit chute, and releasingthe emptied trays into said tray exit chute.

10. In a furnace for heat treatment, a heat treating chamber having aninlet opening at one end and spaced exit chutes for work and for workcarrying trays at the other end, a conveyor movable through saidchamber, trays supported on said conveyor and having pivot hook devices,and a rotatable holder positioned adjacent said exit chutes and havingcooperating hook engaging members for lifting one end of said trays and.moving said trays bodily, whereby said holder engages said tray hookdevices to permit swinging movement of said trays over said work exitchute for releasing the work, and to carry said trays over said trayexit chute for releasing the trays.

11. In a furnace for heat treatment, a heat treating chamber having aninlet opening at one end and spaced exit chutes for work and for workcarrying trays at the other end, spaced conveyor chains movable throughsaid chamber and extending over said work exit chute and terminatingadjacent said tray exit chute, said chains having vertical projectingmembers, a tray support hearth plate between said chains terminatingadjacent said work exit chute, and work carrier trays having lateralprojections adjacent one end adapted to be engaged by said projectingchain members, whereby said trays are pulled over said hearth plate andswing over said work exit chute to release the work and. are carriedover said tray exit chute to be released thereto.

12. In a furnace for heat treatment, a heat treating chamber, saidchamber having an exit chute for work and a second exit chute for traysin the lower portion thereof, means for conveying a work carrying traythrough said chamber and over said chutes and for supporting said trayin work carrying position until it passes over said first exit chute,and means detachably engaging said tray for swinging support over saidfirst chute and for releasing said tray over said second chute, wherebythe tray swings under the influence of gravity to release the work intothe first chute and is then released to enter the second chute,

CARL I. HAYES.

